AKlowriderZ71

iTrader: (22)

The ported 317's have more power potential if used on a bigger build. If you have a build like that planned in the future, keep them & put the stock heads back on the 5.3, I bet the 5.3 will wake up a bit, and you'll have a nice set of heads for the future.

Or sell the truck just like it is and save yourself the work and cost of gaskets.

tweeder

iTrader: (3)

I'm curious how much of a difference there is. If I get the full 10 lbs changing back to stock then it's worth my time, as that's double the power. But will the stockers hold up that way I can sell the 317's as complete.

Mangled03gmc

iTrader: (95)

Yes the heads are heads.. Stockers will be fine. While you have them off ( stockers) have a nice PP job done..

AKlowriderZ71

iTrader: (22)

I run 12 psi on my stock 5.3 heads. No problems with them holding up.

BTW, going from 5 to 10 psi might be "twice the boost", but it is not "twice the power". But it is a HUGE increase in power. You WILL notice it.

I predict that going back to the stock heads will put you around 8-9 psi.

08cheyennesc

iTrader: (2)

When i did my headers and high flow cats my boost went down from 8 to 6. Had to put a 3.7" pulley and now is 10#.

tweeder

iTrader: (3)

Do I need to change the springs with my cam? Here are the specs.

http://www.compcams.com/Cam_Specs/Ca...csid=1085&sb=2

tweeder

iTrader: (3)

I was thinking about a smaller pulley also. I could go with a 2.50 for 11-12 psi. They also have a 2.25 but has supposed to be for the xa-1a though.

tweeder

iTrader: (3)

I once read that on a properly tuned engine, each psi is worth 20 hp.

AKlowriderZ71

iTrader: (22)

Your yellow springs are probably okay. Stock rocker arms, right?

tweeder

iTrader: (3)

Yep..